Diplomystus Fossil Fish
The Diplomystus Fossil Fish is an ancient freshwater type of Herring, which comes for the Eocene Age. The fossil fish is found in limestone shale that can be dug on private property at the Green River formation in Kemmerer, Wyoming.
The Green River Formation is considered one of the largest deposits of sedimentary rock in the world. The formation dates as far back as 50 million years ago. The area covers more than 25,000 square miles and is roughly about 2000 feet in thickness. The multiple lakes were formed by past geological events that lifted the Rocky Mountains long ago.
Unlike the humid and subtropical climate at the time the Diplomystus Fossil Fish were swimming the waters. The Green River Formation area located in southwestern Wyoming, eastern Utah, and western Colorado is now much like a desert. In the Eocene time the area was full of lakes, vegetation, wildlife, making it a much different Eco system. Over time the climate change and the area dried up causing extinction making way for the fossils to occur.
The first Diplomystus Fossil Fish uncovered in the Green River Formation occurred in 1856. All the fossil fish displayed on our web site come from the Fossil Lake area near Kemmerer, Wyoming USA. Found at the 7200 foot elevation this area has been commercially mined since the late 1800 hundreds.
Fossil do have some preparations and does not detract from the quality or value of the specimen.
Our information comes from several sources, you can find more to read and learn about the formation here.
The fossil is embedded in a line stone plate which measures 5 7/8″ long X 3 1/8 wide x 1/4 thick.